# How to step to the next line using option n of Debugger.jl julia?

**URL:** <https://discourse.julialang.org/t/how-to-step-to-the-next-line-using-option-n-of-debugger-jl-julia/29483>\
**Category:** General Usage\
**Created:** [October 4, 2019, 11:32am UTC](https://discourse.julialang.org/t/how-to-step-to-the-next-line-using-option-n-of-debugger-jl-julia/29483 "2019-10-04T11:32:34Z")\
**Posts on this page:** 7\
**Page:** 2

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**Author:** ![bsnyh](https://avatars.discourse-cdn.com/v4/letter/b/ce7236/32.png) [@bsnyh](https://discourse.julialang.org/u/bsnyh)\
**Post date:** [October 22, 2019, 7:23am UTC](https://discourse.julialang.org/t/how-to-step-to-the-next-line-using-option-n-of-debugger-jl-julia/29483/21 "2019-10-22T07:23:36Z")

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I tried this earlier and I’m trying this now. Both times do not work. This time,

```julia
Julia> using Juno
Julia> Juno.@enter split("hello, world", isspace)

```

It takes a long time to run, like forever, with a relative quick computer… it is unacceptable.

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**Author:** ![pfitzseb](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/pfitzseb/32/45566_2.png) [@pfitzseb](https://discourse.julialang.org/u/pfitzseb)\
**Post date:** [October 22, 2019, 7:25am UTC](https://discourse.julialang.org/t/how-to-step-to-the-next-line-using-option-n-of-debugger-jl-julia/29483/22 "2019-10-22T07:25:36Z")

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Yeah, the macro invocation itself works, but the REPL input is broken as you observed above:

> Thank you for your quick reply. I finally roughly figure out why do I get the feedback message “no previous command executed”. Somehow I typed “n” and then press enter, but debugger does not get it. Debugger understands it as “nothing”, which literally means nothing is typed… sigh. In this case, it will execute the previous command. But there is no previous command.

> [@bsnyh](#):
>
> It takes a long time to run, like forever, with a relative quick computer… it is unacceptable.

`Juno.@enter split("hello, world", isspace)` takes less than 10s on my machine until it drops you into the debugger. The second invocation is basically instant.

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**Author:** ![tim.holy](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tim.holy/32/52_2.png) [@tim.holy](https://discourse.julialang.org/u/tim.holy)\
**Post date:** [October 22, 2019, 7:28am UTC](https://discourse.julialang.org/t/how-to-step-to-the-next-line-using-option-n-of-debugger-jl-julia/29483/23 "2019-10-22T07:28:33Z")

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Are you sure that’s not just the usual “Julia has to compile methods the first time you call them” latency? It should not be too bad on the second try.

Also, why are you calling `using Juno` from the REPL? Either you should start a plain REPL (e.g., from the linux prompt) or you should start atom and be using Juno already. Then:

- if you’re in a plain REPL, use Debugger.jl and the `s`, `n`, etc. commands to advance to the next line. If you want to see the value of a variable, hit ` so that you enter the “julia” mode (and hit backspace to return to “debug” stepping mode)
- if you’re in Juno, use the GUI tools to step. You’re effectively already in the variable-evaluation mode, anything you type on the command line gets interpreted within the scope of the program. In other words, in Juno you don’t use the `s`, `n`, etc. commands

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<div class="post-metadata">

**Author:** ![bsnyh](https://avatars.discourse-cdn.com/v4/letter/b/ce7236/32.png) [@bsnyh](https://discourse.julialang.org/u/bsnyh)\
**Post date:** [October 22, 2019, 7:34am UTC](https://discourse.julialang.org/t/how-to-step-to-the-next-line-using-option-n-of-debugger-jl-julia/29483/24 "2019-10-22T07:34:45Z")

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I’m using Atom + Linux Ubuntu, so I’m in Juno interface already. But either I miss something, or something misses me. Sigh. it does not work with my Juno.

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**Author:** ![tim.holy](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tim.holy/32/52_2.png) [@tim.holy](https://discourse.julialang.org/u/tim.holy)\
**Post date:** [October 22, 2019, 7:36am UTC](https://discourse.julialang.org/t/how-to-step-to-the-next-line-using-option-n-of-debugger-jl-julia/29483/25 "2019-10-22T07:36:28Z")

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Your screenshot above suggests you’re using an ancient version of Juno. (Yours is still affected by [https://github.com/JunoLab/Juno.jl/issues/264](https://github.com/JunoLab/Juno.jl/issues/264), which was closed an eternity ago by Julia standards 😄.)

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**Author:** ![bsnyh](https://avatars.discourse-cdn.com/v4/letter/b/ce7236/32.png) [@bsnyh](https://discourse.julialang.org/u/bsnyh)\
**Post date:** [October 22, 2019, 7:42am UTC](https://discourse.julialang.org/t/how-to-step-to-the-next-line-using-option-n-of-debugger-jl-julia/29483/26 "2019-10-22T07:42:33Z")

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The screenshot was taken from a weblink, it’s not from my computer. I just checked the Juno package by `using Pkg` and `Pkg.installed()`, the version is v"0.7.2". I guess it is not an ancient version. On the other hand, I remembered I checked the Juno editor package installed, it is actually uber-juno 0.3.0, the official installer of Juno, the Julia IDE. It is the uber-juno who does not work in my computer. Any comments about it?

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**Author:** ![pfitzseb](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/pfitzseb/32/45566_2.png) [@pfitzseb](https://discourse.julialang.org/u/pfitzseb)\
**Post date:** [October 22, 2019, 7:54am UTC](https://discourse.julialang.org/t/how-to-step-to-the-next-line-using-option-n-of-debugger-jl-julia/29483/27 "2019-10-22T07:54:37Z")

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Can you paste Juno’s debug info into a [gist](https://gist.github.com/)? You can get it either from the `Julia Client: Debug Info` command or the `Juno > Debug Information` menu entry.

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